Apparatus for controlling heave pitch and roll of a floating vessel

ABSTRACT

A floating vessel having tanks adjacent both sides and both fore and aft of the vessel, the tanks extending vertically above and below the waterline. Each tank has a series of vertically spaced openings to the outboard side of the vessel, the openings being both above and below the waterline. The size of the openings is adjustable to control the rate at which water fills and empties the level of the water relative to the sides of the vessel rises and falls.

[ Oct. 28, 1975 United States Patent [191 Rodriguez 55 HD 55H 6/ 6 MM l] 1 mmmm m r e r n a w ak 8 e nm w t ShHP 6784 6667 9999 1111 /l// 0 3 7670 0484 9967 7969 3333 APPARATUS FOR CONTROLLING HEAVE PITCH AND ROLL OF A FLOATING VESSEL [75] Inventor: oatiguin R. Rodriguez, Cerritos, FOREIGN PATENTS 01R APPLICATIONS 630,638 7/1934 Germany...i.................. 114/125 [73] Assignee: Global Marine, Inc., Los Angeles,

Ca Primary Examiner-Trygve M1. Blix Assistant Examiner-Charles 1E. Frankfort Attorney, Agent, or FirmChristie, Parker & Hale [22] Filed: Sept. 24, 1973 [21] App]. N0.: 400,269

[57] ABSTRACT A floating vessel having tanks adjacent both sides and both fore and aft of the vessel, the tanks extending vertically above and below the waterline. Each tank has a series of vertically spaced openings to the outboard side of the vessel, the openings being both above and below the waterline. The size of the open- 23 I ZOHZ .ll/ 1 wa 5 62 3 ,1 5 6 B3 H .4U u l mDl 15m mu, MRH mu m m m Mae .u S L C0 d s m UmF References Cited UNITED STATES PATENTS ings is adjustable to control the rate at which water fills and empties the level of the water relative to the sides of the vessel rises and falls.

511 m H4 41 ll 1 1,427,526 2,405,115 Creed 3,164,120 Field 2 Claims, 4 Drawing Figures 3 f O 1 t e e h S amt 0m. 28, 1975 iw. I

US, amt Oct. 28, 1975 Sheet2 0f3 3,915,108

US Pamm Oct. 28, 1975 Sheet30f3 3,915,1U8

APPARATUS FOR CONTROLLING HEAVE PITCH AND ROLL OF A FLOATING VESSEL FIELD OF THE INVENTION This invention relates to floating vessels such as ships, barges, floating platforms and the like, and more particular, is concerned with apparatus for adjustably damping the heave roll and pitch of such floating vessels.

BACKGROUND Stabilizing of vessels against heave, pitch and roll is SUMMARY OF THE PRESENT INVENTION In brief, the present invention involves a tuning system for damping the heave, pitch, and rolling motions of a vessel floating in water which involves a plurality of vertically extending tanks positioned along either side of the vessel and extending substantially below and above the waterline. Each tank is provided with a series of openings to the sea, the openings being spaced vertically along the length of each tank. The size of the openings can be adjusted or the openings can be completely closed to the sea.

. For a more complete understanding of the invention, reference should be made to the accompanying drawings wherein:

FIG. 1 is a side elevational view of a vessel incorporting the features of the present invention;

FIG. 2 is a front view of the vessel;

FIG. 3 is a detailed view of the mechanism for open- FIG. 4 is a sectional view taken substantially on the line 4-4 of FIG. 3.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2, there is shown a vessel designed for use as a drilling platform and described in detail in copending application Ser. No. 399,806, filed Sept. 24, 1973, by the same inventor as the present application. While the invention is described with particular reference to the vessel disclosed in the aboveidentified copending application, the invention is not limited to use in any particular type of vessel and has application to conventional ship-shape vessels as well.

In the vessel as shown, the numeral indicates generally a drilling vessel incorporating the features of the present invention. The vessel 10 includes a pair of vertical hulls, indicated generally at 1'2 and 14, joined at the top by a bridging platform indicated generally at 16. The platform includes a main deck 18 and a lower deck 20 which are rigidly tied together by box girder by means of suitable tubular reinforcing members, including a plurality of horizontal cross members 22 extending between the hulls 12 and 14 above the waterline. The horizontal cross members 22 in turn aretied to the underside of the platform 16 by upright tubular sections 24 and diagonal cross braces 26.

The vertical hulls l2 and 14 terminate at their lower ends in torpedo-shaped sections 28 and 30, respectively. Each of the torpedo-shapedsections includes a cylindrical portion extending the length of the hull which is of somewhat larger diameter than the beam width of the remainder of the hull. The torpedo-shaped sections have a hemispherical bow 32 at one end and a tapered stern section 34 at the other end. A propeller 36 extends beyond the end of the stern section and is surrounded by a protective shroud 38. The propellers are driven by suitable motors (not shown) mounted in the interior of the stern section. The torpedo-shaped sections at the lower ends of the hulls are rigidly joined together by horizontal cross members 40, which, as shown in FIG. 2, are preferably oval shaped in crosssection to reduce resistance to movement through the water.

Considering the design of vertical hulls in more detail, each hull is constructed of bulkheads and outer plates welded together to form a rigid watertight structure. Each hull comprises a pair of substantially parallel side walls and 52 which extend vertically from beneath the lower deck 20 down to the junction with the outer skin of the cylindrical lower section 28. The bow 53 and stem 55 of the hulls are semi-cylindrical in form, for example, to reduce drag in moving through the water.

The interior of each hull is compartmentalized by a series of vertical bulkheads 57.. The vertical bulkheads are used in combination with the side walls 50 and 52 of each hull to form vertically extending tanks 58, 60, 62 and 64. The tanks are arranged in pairs with two of the tanks in the forward part of the hull and two of the tanks in the aft portion of the hull. The tanks are sealed off at either end by bottom walls 66 and top walls 68. The top and bottom walls are positioned such that the tanks extend vertically substantially above and below the waterline.

Each of the vertical tanks is provided with a series of vertically spaced openings 70 [located on the outboard side of the respective hulls l2 and 14. As best seen in FIGS. 3 and 4, the size of the openings may be varied by rotatably supported plates or louvers 72 positioned inside the tanks opposite each of the openings 70. Each plate 72 is supported on a shaft 74 extending horizontally across the center of each of the openings 70, the

, shaft 74 being supported at either end from the inside construction. The vertical hulls l2 and 14 are secured of the side plates forming the outer side wall of the hull by suitable angle brackets 76 and 78. .lournaled on the shaft 74 are a pair of supporting arms 80 and 82 which I are secured at one end to the plate 72 and are connected at the other end by a shaft 84. A vertically extending connecting rod 86, journaled on each of the shafts 84, extends upwardly through an opening 88 in the top wall 68 of the tank. An hydraulic actuating cylinder 90 is pivotally supported at one end in a clevis 92 mounted on the top wall 68. The piston rod 93 of the cylinder 90 in turn is pivotally coupled to the top of the connecting rod 86, as indicated at 92. The top of the connecting rod 86 is also movably supported from the side wall 52 by a link 94.

As shown in FIGS. 3 and 4, the movable plates 72 are shown in the closed position in which the openings 70 are substantially closed off. Energizing of the hydraulic cylinder 90 lifts the connecting rod 86, thereby rotating the arms 80 and 82 so as to move the plates 72 into an open position, as indicated by the dotted lines in FIG. 3.

The tanks 58, 60, 62, and 64 and the fore and aft portions of each of the hulls operate to reduce the vertical movement of the vessel. This vertical movement or heave reponse is due to the cyclical change of buoyancy in the vessel resulting from the rise and fall of the water by passing wave action. For a conventional vessel there is no control over such changes in buoyancy as the boat rides and falls. However, with the tanks of the present invention open to the sea, water flows into and out of the tanks as the water level rises and falls, so that the total weight of the vessel also varies in a cyclical manner. As the change in buoyancy causes the level of the vessel in relation to the level of the water to change, water either flows into the tanks or flows out of the tanks through the openings 70. The change in water level in the tanks and therefore the change in the weight of the vessel varies cyclically at the same frequency-as the cyclical changes of buoyancy due to wave action. By adjusting the openings to the tanks, the phasing of the two actions can be adjusted so that an increase in buoyancy is counteracted by an increase in weight. The apparent change of buoyancy therefore stays more nearly constant, thereby reducing the net force causing the level of the ship to rise and fall with wave action.

pitch of the vessel.

In the preferred embodiment, all of the openings through the sides 50 are shown as being equal in area. However, the openings need not be of equal size. The top openings, for example, generally function only to allow air to enter and escape from the volume above the surface of the water and may therefore be made smaller in area without materially changing the operation. Also, the size of the openings below the waterline may be adjusted in size independently of the openings above the waterline.

What is claimed is:

l. A vessel comprising a hull including a plurality of vertically extending tanks, each tank having a series of openings through side walls thereof on the outboard sides of the hull, the series of openings in each tank being arranged vertically with a plurality of openings in each series being below the waterline and a plurality above the waterline, whereby the openings in each series are covered sequentially by a rise in the level of the water along the sides of the vessel, and means for adjusting the sizes of said openings to control the rate at which water passes between the tanks and the outside of the vessel comprising plates mounted in the openings and rotatable about horizontal axes, the plates when in an open position extending outwardly of the sides of the vessel.

2. Apparatus as defined in claim 1 wherein said adjusting means further includes hinge means inside the tank mounting the respective plates to the tank, the hinge meanssupporting the plate for rotation about a horizontal axis positioned substantially opposite the central part of the plate and inside the side wall, the plate being narrower than the adjacent opening, and means rotating the plates from a position parallel to the side wall to a position extending a substantial angle to the side wall, said means locking the plates in any selected angular position. 

1. A vessel comprising a hull including a plurality of vertically extending tanks, each tank having a series of openings through side walls thereof on the outboard sides of the hull, the series of openings in each tank being arranged vertically with a plurality of openings in each series being below the waterline and a plurality above the waterline, whereby the openings in each series are covered sequentially by a rise in the level of the water along the sides of the vessel, and means for adjusting the sizes of said openings to control the rate at which water passes between the tanks and the outside of the vessel comprising plates mounted in the openings and rotatable about horizontal axes, the plates when in an open position extending outwardly of the sides of the vessel.
 2. Apparatus as defined in claim 1 wherein said adjusting means further includes hinge means inside the tank mounting the respective plates to the tank, the hinge means supporting the plate for rotation about a horizontal axis positioned substantially opposite the central part of the plate and inside the side wall, the plate being narrower than the adjacent opening, and means rotating the plates from a position parallel to the side wall to a position extending a substantial angle to the side wall, said means locking the plates in any selected angular position. 